The subject matter disclosed herein relates to the fabrication and use of radiation detectors, including X-ray radiation detectors, configured for use in high resolution imaging contexts.
Non-invasive imaging technologies allow images of the internal structures or features of a subject (patient, manufactured good, baggage, package, or passenger) to be obtained non-invasively. In particular, such non-invasive imaging technologies rely on various physical principles, such as the differential transmission of X-rays through the target volume or the reflection of acoustic waves, to acquire data and to construct images or otherwise represent the internal features of the subject.
Computed Tomography (CT) scanners operate by projecting fan-shaped or cone-shaped X-ray beams from an X-ray source. The X-ray source emits X-rays at numerous view angle positions about an object being imaged, such as a patient, which attenuates the X-ray beams as they traverse the object. The attenuated beams are detected by a set of detector elements which produce signals representing the intensity of the incident X-ray beams. The signals are processed to produce data representing the line integrals of the linear attenuation coefficients of the object along the X-ray paths. These signals are typically called “projection data” or just “projections”. A 3D image volume of the imaged object can be reconstructed using different reconstruction techniques, such as filtered-back projection, to allow the visualization of the internal structures. The images may in turn be associated to represent a volume or volumetric rendering of a region of interest. In a medical context, pathologies or other structures of interest may then be located or identified from the reconstructed image volume.
In certain imaging contexts, it is desirable to introduce a focal spot “wobble” mode in a given CT system. Such an operation mode typically involves alternating between two or more spatially offset focal spot locations on an X-ray generating target at some or all of the view angles. Such a wobble can be applied to both radial and longitudinal directions in a CT system to improve in-plane and z-direction spatial resolution as well as reducing the aliasing artifacts with improved spatial sampling, effectively increasing the number of projections views for each gantry rotation.